U.S. patent number 4,295,299 [Application Number 06/083,133] was granted by the patent office on 1981-10-20 for steel clad wood door frame.
This patent grant is currently assigned to United States Gypsum Company. Invention is credited to David M. Nelson.
United States Patent |
4,295,299 |
Nelson |
October 20, 1981 |
Steel clad wood door frame
Abstract
A door frame comprising wood frame members including a strike
jamb, a hinge jamb, and a header, said frame members each being
recessed longitudinally to provide a rabbet having a major surface
and a minor surface perpendicular to said major surface, a slot
substantially coplanar with the major surface of said rabbet
extending into a non-recessed portion of said member, and a
substantially J-shaped metal frame reinforcing member having a
major flange, a minor flange substantially parallel to said major
flange, and a connecting web substantially perpendicular to said
major and minor flanges, said minor flange engaging the major
surface of said rabbet and extending into said slot, and the major
flange of said reinforcing member extending in engagement with the
outer surface of said member.
Inventors: |
Nelson; David M. (Kewanee,
IL) |
Assignee: |
United States Gypsum Company
(Chicago, IL)
|
Family
ID: |
22176396 |
Appl.
No.: |
06/083,133 |
Filed: |
October 9, 1979 |
Current U.S.
Class: |
49/504; 292/246;
292/346; 52/514 |
Current CPC
Class: |
E06B
1/34 (20130101); Y10T 292/087 (20150401); Y10T
292/79 (20150401) |
Current International
Class: |
E06B
1/04 (20060101); E06B 1/34 (20060101); E06B
001/04 () |
Field of
Search: |
;49/503,504,460 ;70/542
;292/346 ;52/514 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Downey; Kenneth
Attorney, Agent or Firm: Kurlandsky; Samuel Robinson; Robert
H. Roberts; Kenneth E.
Claims
Invention is claimed as follows:
1. A door frame comprising wood frame members including a strike
jamb, a hinge jamb, and a header, said frame members each being
recessed longitudinally to provide a rabbet having a major surface
and a minor surface perpendicular to said major surface, a slot
substantially coplanar with a major surface of said rabbet
extending into a non-recessed portion of said member and along
substantially the entire length of said member, and a substantially
J-shaped metal frame reinforcing member extending along
substantially the entire length of said member and having a major
flange, a minor flange substantially parallel to said major flange,
and a connecting web substantially perpendicular to said major and
minor flanges, said minor flange engaging the major surface of said
rabbet and extending into said slot, and the major flange of said
reinforcing member extending in engagement with the outer surface
of said member.
2. A door frame according to claim 1, wherein the metal of which
said reinforcing member is made is steel.
3. A door frame according to claim 2, wherein said metal
reinforcing member is provided with openings to permit nails to
pass therethrough.
4. A door frame according to claim 2, wherein decorative molding
strips cover the edges of each of said members.
5. A door frame according to claim 2, wherein the minor face of the
rabbet of said strike jamb has a magnetic weatherstripping affixed
thereto, and the minor face of the rabbet of said hinge jamb has a
compressible weatherstripping affixed thereto.
6. A door frame according to claim 2, wherein the minor flange of
said reinforcing member is recessed for receiving a hinge
flush-mounted therein.
Description
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to doors, and is more particularly
concerned with a door frame constructed primarily of wood, and
having a metal cladding surrounding a portion of the frame.
(2) Prior Art
It has been conventional to construct door frames of wood. Wood
frames are easy to construct and provide good thermal insulation.
However, wood is not as strong as might be desired, and a large
percentage of forced entries are gained through failure of the wood
frame. More recently door frames made entirely of steel have
appeared on the market. The use of steel solves the security
problem, but results in thermal problems because of the fact that
steel conducts exterior temperatures to the interior of the
dwelling. Steel reinforced wood frames have entered the market and
add some rigidity to the entire frame, but these frames have
provided no protection in the lock and hinge areas.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a door frame
formed primarily of wood in order to provide good thermal
insulation.
It is another object of the invention to provide a door of the type
described in which protection is provided against forced entry in
the areas of the lock and hinges.
It is further an object to provide a door frame of the type
described which may be readily constructed of available materials
and which is relatively inexpensive to produce.
Still other objects and advantages of the invention will readily
present themselves to one skilled in the art upon reference to the
following specification, the drawings, and the claims.
According to the invention, a door frame is provided formed
primarily of wood frame members including a strike jamb, a hinge
jamb, and a header. Each frame member is recessed to form a rabbet
for receiving the edges the door in the closed position. A metal
cladding, preferably of sheet steel is provided around portions of
the rabbeted areas, and particularly in the lock area and the hinge
area. As a result, the door retains its thermal insulation
properties, yet offers excellent protection against forced
entry.
BRIEF DESCRIPTION OF THE DRAWING
In the drawings,
FIG. 1 is an elevational view of a door and frame according to the
invention.
FIG. 2 is a fragmentary cross-sectional view taken at the line 2--2
of FIG. 1, looking in the direction of the arrows, and
FIG. 3 is a perspective view of the hinge jamb and associated
structures.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a door 10 having a knob 11 is shown mounted in
a door frame 12. The door frame 12 comprises interior trim moldings
13, 14 and 15 which cover a strike jamb 16, a hinge jamb 17, and a
header 18, respectively. The jamb and header structures are not
visible in FIG. 1. The door 10 is hingedly mounted on the frame 12
by means of hinges 19.
Referring to FIGS. 2 and 3, portions of the hinge jamb are shown in
detail. Since cross-sectional views of the strike jamb 16 and
header 18 are almost identical to that shown in FIGS. 2 and 3,
these structures are not shown in the drawings in detail. The hinge
jamb is comprised of a wood base 21 which is recessed
longitudinally to provide a rabbet 22 having a major face 23 and a
minor face 24. A slot 25 is provided substantially coplanar with
the major face of the rabbet, and extending a limited distance into
the non-rabbeted portion of the wood base 21.
In order to provide protection against forced entry, a J-shaped
metal cladding or reinforcing frame 26 is mounted over the rabbeted
portion of the wood base 21 and comprises a major flange 27, a
minor flange 28 and a connecting web 29 which covers the inner
exposed edge of the hinge jamb. The reinforcing frame 26 is so
arranged that the major flange is in contact engagement with the
unrabbeted surface of the wood base 21 and the minor flange is in
contact engagement with the major face 23 of the rabbet 22 and
extends into the slot 25. The connecting web 29 forms the edge of
the hinge jamb 17.
The remainder of the building structure to which the jamb is
attached comprises a brick molding 33, an outer sheeting 34, wood
studs 35 and 36, and a sheet of dry wall 37. Interior trim 16
covers the connecting web 29 and laps over the dry wall 37.
Referring to FIG. 3, a hinge recess 39 is shown provided in the
minor flange 28 of the reinforcing frame. A nail slot 40 is shown
provided in the connecting web 29 to permit nails 41 to pass
therethrough and to engage the wood portion of the hinge jamb 17.
Other slots, not shown, may be provided in the reinforcing frame 26
to permit nails to pass into stud 35, as shown in FIG. 2.
In FIG. 2 the door 10 is shown positioned in the space defined by
the rabbet 22, and includes a metal skin 45 and a plastic foam core
46. A vinyl thermal break 47 is provided to fasten the free edges
of the metal skin and to prevent heat from being transferred from
one skin to the other. Flexible vinyl compression type
weatherstripping 44 is affixed to the minor surface 24 of the
rabbet 22 to provide thermal insulation when engaged by the door
10. Magnetic type weatherstripping may be affixed in similar manner
to the strike jamb.
The door frame of the present invention has several advantages over
existing door frames. First, it utilizes primarily wood jambs which
are easy to construct and which provide good thermal insulation.
Second, by providing a steel reinforcement frame over the portion
of the jambs subject to forced entry, it provides the jambs with
sufficient strength to prevent such forced entry. In order to gain
illegal entry through the door, a person would have to deform the
steel reinforcing security frame instead of merely breaking out the
wood frame. In the present structure the steel encloses the wood of
the jamb starting at the top, extending across the jamb face,
bending around the interior edge of the frame, and extending
approximately 3/4 of the way across the underside of the frame. The
frame is attached to the rough opening through the outer layer of
steel, thus securing the frame in the opening. The lock strike
plate and hinges are attached through the outer layer of steel and
into the wood, thus anchoring them to the steel and frame. Since no
steel is exposed to exterior temperatures, there is no thermal
problem involved. In practice the steel reinforcing members may
extend the entire length of each jamb. Alternatively, the
reinforcing members may be placed solely in the areas of the lock
and the hinges.
It is to be understood that the invention is not to be limited to
the exact details of construction or operations or materials shown
and described, as obvious modifications and equivalents will be
apparent to one skilled in the art.
* * * * *